Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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The present invention rela-tes to a me-tal pipe having
proper-ties with regard to manufacture, handling and use that
are considerably improved in relation to previously known
types of pipes.
Pipes manufactured from steel, stainless steel and
other metallic materials, are normally manufactured and sup-
plied in lengths, suitable for storaye, transport and handling
when used. A general restriction in this respect is the
lenyth of the vehicles used for transport of the pipes. In
use, considerably longer lengths of pipe are often required,
and the pipes are therefore ~oined by means of welding, pipe
couplings or -the like, to required pipe leng-th. For those
applications in which the pipes should have a varied longitu-
dinal direction of extension, special pipe bending tools are
usually re~uired. For applications, in which the pipes are
located below the ground surface, there are also problems
caused by se-ttlemen-t in the ground layers, based on, for exarn-
ple changes in ground water level and temperature. As a re- I
sult, the plpes often burst, and, for example wi-th regard to
pipes carrying wa-ter or gas, result in considerable inconve-
nience. Such bursts can also occur due to changes in the
leng-th caused by temperature variations. Changes in the
length extension have previously been compensa-ted ~or by
attachment of movemen-t equalizing compensators at spaced loca-
tions along the total extension of a pipe line.
The present invention provides a metal pipe, which
can be manufactured and supplied in considerably longer
leng-ths than prevlously practically possible, and thus elimi-
nates, or considerably reduces, the number of joints alony the30
total ex-tension of a pip~ line. It is further possible to
store and transport extremely long lengths of pipe with a con-
siderably reduced space requirement than what has previously
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beel-l re(~arded as possible. ~ reduction in the nulllber of
illtS also result in improved resistance against corros.lur
an~ buLs-ts, and the resistance against bursts cause~ by
c~ es in len~h ex~enslon is also conslderably irnproved,
Witllout at-tachlnent oE compensators. Furthermore, the pipe
accordirlg to the presen-t inven-tion offers -the possibi.li-ty of
an :inlproved flow characteristics in relation to previously
used -types of pipes.
According to the present invention there is provided
a metal pipe, comprisi.ng, as a continuous length of plpe, por-
tions llaving a substantially smooth wall surface separated
Erom each other by means of intermediately locat~d w~lv~sh~pod
or creased portions shaped from the pipe length, sa:id wave-
shaped or creased portions being hobbings or stampings which
only partly surround the circumference of the pipe length and
hav:irlg an ex-ternal diame-ter subs-tan-tially corresponding to -the
external diameter of intermediately loca-ted portions of -the
me-tal pipe, the hobbing or stamping depth being maintained
substantially constant in -the entire extension of surrounding
waveshaped or creased portions.
In one embodiment of the present inven-tion said
intermedia-tely located waveshaped or creased portions are sep-
arated in-to two parts by two intermediately located and longi-
tudinally extending substantially smooth surfaces, located in
an opposed relationship to each other.
In ano-ther embodimellt of the present invention a
metal pipe in which the intermedia-tely located waveshaped or
creased por-tions are separated into at least three parts by
means of intermediately loca-ted and longitudinally extending
subs-tantially smooth surfaces. Suitably the intermediately
loca-ted waveshaped or creased portions have ad~acently loca-ted
waves or creases with individually d.ifferent annular exten-
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sions. A:Lterrlatively, the intermediately loca-ted waveshaped
or creased portions have adjacently located helically extend-
ing waves or creases.
In ano-ther embodiment o~ -the presen-t invention a
metal plpe includes at least two waveshaped or creased por--
tions, parkly surrounding the pipe length, having adjacen-tly
located waves or creases extending helically with substan-
tially an equal pltch. Suitably the intermedia-tely located
waveshaped or creased portions comprises mu-tually separated
embossments, located angularly rota-ted or displaced in rela-
tion to each other with regard to adjacently located turns.
Deslrably the pipe length includes a plurali-ty o~ substan-
tially equispaced said intermediately loca-ted waveshaped or
creased portions said portions being similar or dissimilar to
each other. Alternatively the pipe length includes a plural-
ity of non-equi-spaced said intermediately located waveshaped
or creased portions, said portions being similar or dissimilar
to eacil other. Suitably the metal pipe is bent in the region
of said in-termediately located waveshaped or creased portions
into a substan-tially circular configuration having ad~acently
located winding turns.
The present invention will be further illustrated by
way of the accompanying drawings, in which:-
Fig. 1 shows a perspective view of a metal pipe
leng-th;
Fig. 2 shows a longitudinal sectional view of the
plpe shown in Fig. l;
Fig. 3 shows a perspective view corresponding to
Fig. 1, bu-t with the pipe length slightly rrlodified;
Fig. 4 shows a longitudinal sectional view of -the
pipe shown in Fig. 3;
Fig. 5 shows a perspective view of a length of metal
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pipe accor~ing to one embodiment of the present invention;
~ 'ig. 6 SilOWS a lonyitudinal sectional view of tile
pipe s}-lown ln Fig. 5;
Fig. 7 shows by way of example how a metal pipe ac-
cordirlg to the present invention, when loca-ted on an irregular
surface, adjusts to the extension of -the surface; and
Fig. 8 shows a perspective view of a metal pipe
length wound in-to a plurality of adjacently located wlndings.
Fig.s 1 and 2, illustrate a me-tal pipe comprising a
plurality of successive and preferably cylindrical tubular
por-tions 1, 1', separated from each o-ther and from cy:l:lndrical
end portions 2, 2' by means of bellows-shaped portions 3, 3',
3". Said bellows-shaped portions 3, 3', 3~' comprise adja-
cen-tly loca-ted and surrounding hobbings or stampings, forming
a substan-tially waveshaped section, as shown in Fig. 2. The
pipe length shown in Fig.s 1 and 2 may include any desired
number of bellows-shaped portions 3, 3', 3", separated from
each other by means of intermediately loca-ted cylindrical por-
tions 1, 1'. The bellows-shaped portions 3, 3', 3", the
:Length of which in rela-tion to intermediately loca-ted cylin-
drical portions 1, 1' obviously can be different from what is
shown, allows the pipe length to be changed, bo-th with regard
to -total length, as well as with regard to direc-tion oE exten-
sion.
The metal pipe will thus permit two adjacently lo-
ca-ted cylindrical portions 1, 1' to be located at mu-tually
diEfererlt angu:Lar directions and the intermedia-tely located
bellows-shaped portion 3' accommodates this change with com-
pression of the portion having the smaller radius, and expan-
SiOIl oE the opposite side.
Ilowever, -to arrange the bellows-shaped portlons 3,
3', 3" as a p:Lurality oE surrounding and adjacently loca-ted
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annular folds or waves has the disadvantage tha-t turbulence
can occur in a medium flowing through the pipe leng-th when
passiny the bellows-shaped portions 3, 3', 3". This can sub-
stantially be avoided by modi.-fication of the shape of -the bel-
lows-shaped portions 3, 3' 3", and an example of such a modi-
fication is shown in Fig.s 3 and 4. The centrally located
be:llows-shaped portions 3' has been modified into a surround-
ing fold wave having an helical line of extension, the en-
trance and exit preferably being arranged successively in-
creasing/decreasing with regard to the height o.E the :Eold orwave.
By selecting a suitable pitch for such a he:Lical
portion 3', based on the flow rate for the mediulll to flow
through the pipe, a most desirable effec-t can be achieved,
- since the flowing medium thereby is guided into a ro-tary flow
movelllen-t, which causes -the medium to follow the comple-te in-
ternal surface of the pipe. As a result, existing contamina-t-
ing substances that could cause corrosion are carried away,
and when transpor-ting a liquid medium, it is also avolded that
~0 existing air or gas wi-thin the pipe only contac-ts a restric-ted
part of the pipe, usually the internal and upper surface,
which for e.g. water pipes results in a risk for corrosion in
the in-termediate zone between air/water. When the pipe is
used for transport of a gaseous medium, the previously men-
tioned rotary flow movement also causes condensed wa-ter or
similar to be carried away with the gas stream. The embodi-
men-t shown in Fig.s 3 and 4 is arranged with bo-th circularly
and helically extending bellows-shaped portions 3, 3', 3", but
only one of these types, such as the helically extending por-
tions 3', can obviously be used for a pipe length. Further-
more, each helically extending portion 3' may also be formed
by means of a plurality of each other ad~acently located heli-
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ca:L fo:Lcls or waves, having a substantially correspondingpltcil, alld :inclivldual en-trances and exits.
I-t i.s also possible to further modify the metal plpe
and ~ml~odim~n-t of such ~urther modi.fica-tlons i~ acc~rlarlce
with the presen-t invention are shown in Fig.s 5 and 6. Said
Figures include a first alternative embodiment, according to
which the previously mentioned bellows-shaped portions 3, 3 ,
3 only semi-surround the pipe, whereby said portions 3, 3 ,
3 inc]ude a part having a smooth internal surface. The rea-
.lO Son for this is to remove the problems previously discussedwith reference to the embodiment of Fig. 5 3 and ~, i.e. that
pipes used for transport of a liquid, e.g. wa-ter, often re-
ceive damage due to corrosion in the intermedlate zone be-tween
air/water with regard to the upper portion of a horizon-tally
extending pipe, as well as that pipes used for transport of
gas often receive liquid deposits in the lower and internal
bottom portion of the pipe. In order to move e.g. a liquid
deposi-t loca-ted at the lower internal portion of a pipe used
for gas transport, said internal surface should preferably be
completely smooth. The present lnvention ca-ters for -this de-
sired feature by locating the smoo-th part of the bellows-
shaped portion 3, 3 , 3 as lower portions when :Lns-talling a
pipc. wi-th regard to pipes used for -transport of liquid, said
smoo-th par-t is advantageously loca-ted as an upper por-tion, in
order -to cause transport of existing air or gaseous medium to-
gether with the flowing liquid medium. There is thus no risk
for formation of gas or air pockets at the lnternal upper por-
tion.
The above disclosed semi-surrounding bellows-shaped
portions 3, 3 ,3 are preferably arranged surrounding a-t
least 50% of the total peripheral circumference of t~-le pipe,
in order to facilitate accep-tance of changes in -the length ex-
~Z373~S
-tensiorl of t~le pipe. Furthermore, the semi-surroundirlg bel-
lows-shaped por-tions 3, 3', 3~' may advan-tageously be arranged
as two por-tions, internally separated by means of smooth
parts. When installed, the separa-ted bellows-sllaped portions
3, 3', 3~' are advantayeously located on the left or right hand
side of the pipe, whereby both the bottom portion and the top
portlon of the pipe comprises smooth surfaces, which separate
the two par-ts of the bellows-shaped portions 3, 3', 3".
The bellows-shaped portions 3, 3', 3" may further be
arranged either as ringshaped parts located adjacent to each
other, or as helically extending members, basically comparable
with -the prevlous disclosure with reference to ~'ig.s 3 and ~.
In the latter case, -there is a further advantage, since a
medium flowing through the pipe receives a rotary flow,
whereby the previously discussed advantageous flow character-
istics is achieved in combination with the smooth parts, and
hereby it is further avoided that nondesirable deposits of
liquid or gas will remain within the pipe.
The fact that one or two portions of the peripheral
part of the pipe are not bellows-shaped portions 3, 3', 3" re-
sults substantially only in advantages, since large flexibil-
ity is maintained, which, when installed below the ground sur-
face, resul-ts in extremely good properties with regard to set-
tlemen-t in surrounding ground layers, which cause pipe bursts
for a conventional pipe line. In all embodiments of the in-
vention, this flexibility is of utmost importance, in combina-
tion with the fact tha-t the pipe can be manufactured and sup-
plied in substantially desired lengths, which results in the
possibility to install long pipe lines without any ~oints.
Fig.s 5 and 6 also show a fur-ther àlternative embod-
imerlt, including separated embossments 4, 4', 4" subs-tan-
tially surrounding the pipe, which result in shape adap-table
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portions. With regard to adjacently located turns, the em-
bossments are dlsplaced in relation to each other, thus form-
ing, in combina-tion with intermediately located parts, de-
formable portions 4, 4', 4" having a function corresponding to
the embodiments already disclosed. It should be noted, that
the modifications shown in Fig.s 5 and 6 no-t necessarlly must
be arranged combined as shown, but they can be used individu-
ally or in combination with other types of shaped por-tions.
The previously discussed helical shape can obviously
also be used with regard to the modifica-tions shown in Flg.s 5
and 6, in order to guide the medium flowing through the pipe.
Fig. 7 shows by way of example how a metal pipe ac-
cording to the present invention can be installed adjusted to
the line of the extension for the suppor-t, and this adjustmen-t
is carried ou-t continuously to the supporting structure. As a
result, extremely good adjustment is achieved with regard to
settlelnents or slides in ground layer, and since no conven-
tional pipe joints exist, extremely good safety agains-t pipe
burs-ts ls achieved. This is a significant advantage within
areas where ear-th quakes occur, and where settlements in the
ground layers often result in interruptlons within the distri-
butlon network for water, gas and simllar.
A further and not unimportant advantage ls illus-
trated in Flg. B, which is intended to illustrate how a metal
pipe can be wound with adjacently located windings, thus Eorm-
ing a unit which is easily stored, transported and handled.
Furthermore, a connection 5 is shown extending from the pipe,
established by means of a pipe coupling 6. Since the metal
pipe accordlng to the present invention comprlses of a contin-
uous leng-th of pipe, formed by means of alternatlvely smooth
and substantially cylindrical portions 1, 1' and deformable
non-smooth portions 3, 3', 3" or 4, 4', 4", said first men-
t:Loned SlllOO~h portions 1, 1' can be u-tillzecl for establishirly
pi~)e conrlectiorls wi-th conventional prior art techni~ es, e.g.
by mearls of a pipe coupling of the type disclosed in S~, A
7317194-~, which facilitates establishmen-t of connectlon
against a pi.pe without dividing the pipe.
A fur-ther not unimportant aspect is also, tha-t the
presen-t invention makes it possible to use pipes with consid-
erably reduced wall thickness for a large number of applica-
tions. The wall thickness of a pipe is not decided purely on
basis of the internal pressure imposed by a medium f:Lowing
through the pipe, but a factor deciding wall thickness is
of-ten also the method used for joining and connection. For
many applications, the wall thickness of a pipe is chosen to
facilita-te es-tablishment of a screw thread at the connection
points, or to facilitate joining by means of welding. Since
the pipe according to the present inven-tion can be manufac-
tured as a con-tinuous pipe length without any pipe joints, and
since it includes portions which facilitate connection of an
embracing coupling housing forming a par-t of pipe couplings
for establishment of connection agains-t other pipes without
cu-tting the original main pipe, previous considera-tions rela-t-
ing -to methods of connection are eliminated whcn the wall
thickness of a pipe i.s decided. If for example the pipe
according to the present invention is manufac-tured ~rom stain-
less steel, or any other corrosion resistant metal, a pipe
having smaller wall thickness than previously used types of
pipes can be used for most applications. This advantage re-
sults in lllajor profits, both with regard to wei.ght as well as
the cost. for a pipe line. The shape deformable portlons 3,
3', 3", respectively 4, ~', 4", in the pipe according to the
present invention will, as previously discussed, take up
changes in the length, changes in angular direction. of exten-
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~;~3~3~7~
sion, bu-t also serve as strengthening sec-tions .in relation to
rad.ial forces applied against the pipe, which further
s-tLengthens same and facilitates a reduc-tion of the ~all
-thickness .
The described embodiments of pipes according to the
l?r~7n~ inv~nt~.or~ oAly in~on~d ~ ~H~V~ ~ exa~ Le~.
Thus, the deforlllable por-tions 3, 3', 3" respectively 4, 4', 4"
can obviously be Eur-ther varied with regard to speclfic fields
oi. use, as well as combined in a number oi- different; ways.
The advan-tages of the inven-tion are obvious for all types of
pipes manufactured from a substan-tially rigid and non-:flexible
material are included. An important characteristic fea-ture of
the present invention is, tha-t the pipe comprises al-terna-
tively located sections of subs-tantially srnooth portions 1, 1'
and portions 3, 3', 3" or 4, 4', 4" facilitatLng challges in
length and/or direction of extension for the pipe.
A metal pipe length according to the present inven-
tion can also during manufacture be adapted -to suit a specific
application, i.e. after a predetermined distance be arranged
-to accept a large angular change in direction of ex-tension
during installation, as well as be arranged to accept changes
in length at predetermined spaced locations. This means, that
pipe leng-ths, adapted for specific applica-tions, can be sup-
plied.
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